Castrol GTX is re-engineered with TriShield technology to actively protect against deposit build-up. TriShield attracts, captures and disperses small deposit particles before they become big problems. Engine deposits can turn into a thick, dark substance that can wreak havoc within an engine, building up and clogging oil passages. Deposit build-up can lead to reduced gas mileage, decreased engine performance, and in some cases, engine seizure. Whats worse, once it builds up in an engine, its almost impossible to remove. Unique TriShield technology provides superior deposit protection* Maximum protection against viscosity & thermal breakdown. Ultra-low friction to improve gas mileage*